1 : /*
2 : * Copyright (c) 1997 Kungliga Tekniska Högskolan
3 : * (Royal Institute of Technology, Stockholm, Sweden).
4 : * All rights reserved.
5 : *
6 : * Redistribution and use in source and binary forms, with or without
7 : * modification, are permitted provided that the following conditions
8 : * are met:
9 : *
10 : * 1. Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : *
13 : * 2. Redistributions in binary form must reproduce the above copyright
14 : * notice, this list of conditions and the following disclaimer in the
15 : * documentation and/or other materials provided with the distribution.
16 : *
17 : * 3. Neither the name of the Institute nor the names of its contributors
18 : * may be used to endorse or promote products derived from this software
19 : * without specific prior written permission.
20 : *
21 : * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 : * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 : * SUCH DAMAGE.
32 : */
33 :
34 : /*
35 : * Hash table functions
36 : */
37 :
38 : #include "gen_locl.h"
39 :
40 : RCSID("$Id$");
41 :
42 : static Hashentry *_search(Hashtab * htab, /* The hash table */
43 : void *ptr); /* And key */
44 :
45 : Hashtab *
46 : hashtabnew(int sz,
47 : int (*cmp) (void *, void *),
48 : unsigned (*hash) (void *))
49 14 : {
50 : Hashtab *htab;
51 : int i;
52 :
53 14 : assert(sz > 0);
54 :
55 14 : htab = (Hashtab *) malloc(sizeof(Hashtab) + (sz - 1) * sizeof(Hashentry *));
56 14 : if (htab == NULL)
57 0 : return NULL;
58 :
59 1428 : for (i = 0; i < sz; ++i)
60 1414 : htab->tab[i] = NULL;
61 :
62 14 : htab->cmp = cmp;
63 14 : htab->hash = hash;
64 14 : htab->sz = sz;
65 14 : return htab;
66 : }
67 :
68 : /* Intern search function */
69 :
70 : static Hashentry *
71 : _search(Hashtab * htab, void *ptr)
72 1601 : {
73 : Hashentry *hptr;
74 :
75 1601 : assert(htab && ptr);
76 :
77 1601 : for (hptr = htab->tab[(*htab->hash) (ptr) % htab->sz];
78 3739 : hptr;
79 537 : hptr = hptr->next)
80 1124 : if ((*htab->cmp) (ptr, hptr->ptr) == 0)
81 587 : break;
82 1601 : return hptr;
83 : }
84 :
85 : /* Search for element in hash table */
86 :
87 : void *
88 : hashtabsearch(Hashtab * htab, void *ptr)
89 1094 : {
90 : Hashentry *tmp;
91 :
92 1094 : tmp = _search(htab, ptr);
93 1094 : return tmp ? tmp->ptr : tmp;
94 : }
95 :
96 : /* add element to hash table */
97 : /* if already there, set new value */
98 : /* !NULL if succesful */
99 :
100 : void *
101 : hashtabadd(Hashtab * htab, void *ptr)
102 507 : {
103 507 : Hashentry *h = _search(htab, ptr);
104 : Hashentry **tabptr;
105 :
106 507 : assert(htab && ptr);
107 :
108 507 : if (h)
109 0 : free((void *) h->ptr);
110 : else {
111 507 : h = (Hashentry *) malloc(sizeof(Hashentry));
112 507 : if (h == NULL) {
113 0 : return NULL;
114 : }
115 507 : tabptr = &htab->tab[(*htab->hash) (ptr) % htab->sz];
116 507 : h->next = *tabptr;
117 507 : *tabptr = h;
118 507 : h->prev = tabptr;
119 507 : if (h->next)
120 150 : h->next->prev = &h->next;
121 : }
122 507 : h->ptr = ptr;
123 507 : return h;
124 : }
125 :
126 : /* delete element with key key. Iff freep, free Hashentry->ptr */
127 :
128 : int
129 : _hashtabdel(Hashtab * htab, void *ptr, int freep)
130 0 : {
131 : Hashentry *h;
132 :
133 0 : assert(htab && ptr);
134 :
135 0 : h = _search(htab, ptr);
136 0 : if (h) {
137 0 : if (freep)
138 0 : free(h->ptr);
139 0 : if ((*(h->prev) = h->next))
140 0 : h->next->prev = h->prev;
141 0 : free(h);
142 0 : return 0;
143 : } else
144 0 : return -1;
145 : }
146 :
147 : /* Do something for each element */
148 :
149 : void
150 : hashtabforeach(Hashtab * htab, int (*func) (void *ptr, void *arg),
151 : void *arg)
152 14 : {
153 : Hashentry **h, *g;
154 :
155 14 : assert(htab);
156 :
157 1428 : for (h = htab->tab; h < &htab->tab[htab->sz]; ++h)
158 1921 : for (g = *h; g; g = g->next)
159 507 : if ((*func) (g->ptr, arg))
160 0 : return;
161 : }
162 :
163 : /* standard hash-functions for strings */
164 :
165 : unsigned
166 : hashadd(const char *s)
167 0 : { /* Standard hash function */
168 : unsigned i;
169 :
170 0 : assert(s);
171 :
172 0 : for (i = 0; *s; ++s)
173 0 : i += *s;
174 0 : return i;
175 : }
176 :
177 : unsigned
178 : hashcaseadd(const char *s)
179 0 : { /* Standard hash function */
180 : unsigned i;
181 :
182 0 : assert(s);
183 :
184 0 : for (i = 0; *s; ++s)
185 0 : i += toupper((unsigned char)*s);
186 0 : return i;
187 : }
188 :
189 : #define TWELVE (sizeof(unsigned))
190 : #define SEVENTYFIVE (6*sizeof(unsigned))
191 : #define HIGH_BITS (~((unsigned)(~0) >> TWELVE))
192 :
193 : unsigned
194 : hashjpw(const char *ss)
195 2108 : { /* another hash function */
196 2108 : unsigned h = 0;
197 : unsigned g;
198 2108 : const unsigned char *s = (const unsigned char *)ss;
199 :
200 33072 : for (; *s; ++s) {
201 30964 : h = (h << TWELVE) + *s;
202 30964 : if ((g = h & HIGH_BITS))
203 17680 : h = (h ^ (g >> SEVENTYFIVE)) & ~HIGH_BITS;
204 : }
205 2108 : return h;
206 : }
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